[#67]Gravity Force Generator is implemented.

Godlike · Aug 1, 2017 · 4e607a2 · 4e607a2
1 parent 51fedc9
commit 4e607a2
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Showing 3 changed files with 50 additions and 12 deletions.
diff --git a/Pegasus/include/ParticleForceGenerator.hpp b/Pegasus/include/ParticleForceGenerator.hpp
@@ -10,6 +10,8 @@
 
 #include "Pegasus/include/Particle.hpp"
 
+#define GLM_ENABLE_EXPERIMENTAL
+#include <glm/gtx/norm.hpp>
 #include <glm/glm.hpp>
 
 #include <map>
@@ -40,16 +42,41 @@ class ParticleForceRegistry
     std::map<Particle*, std::set<ParticleForceGenerator*>> mRegistrations;
 };
 
-class ParticleGravity : public ParticleForceGenerator
+class ParticleStaticField : public ParticleForceGenerator
 {
 public:
-    explicit ParticleGravity(glm::dvec3 const& g);
+    explicit ParticleStaticField(glm::dvec3 const& g);
     void UpdateForce(Particle& p) override;
 
 private:
     glm::dvec3 const m_gravity;
 };
 
+class ParticleGravity : public ParticleForceGenerator
+{
+public:
+    explicit ParticleGravity(Particle const& particle, double G = 6.674e-11)
+        : m_particle(particle)
+        , m_G(G)
+    {
+    }
+
+    void UpdateForce(Particle& p) override
+    {
+        glm::dvec3 gravityDirection = m_particle.GetPosition() - p.GetPosition();
+
+        double const gravityMagnitude = 
+            m_G * (m_particle.GetMass() * p.GetMass()) 
+            / glm::length2(gravityDirection);
+
+        p.AddForce(glm::normalize(gravityDirection) * gravityMagnitude);
+    }
+
+private:
+    Particle const& m_particle;
+    double const m_G;
+};
+
 class ParticleDrag : public ParticleForceGenerator
 {
 public:

diff --git a/Pegasus/sources/ParticleForceGenerator.cpp b/Pegasus/sources/ParticleForceGenerator.cpp
@@ -60,12 +60,12 @@ void pegasus::ParticleForceRegistry::UpdateForces()
     }
 }
 
-pegasus::ParticleGravity::ParticleGravity(glm::dvec3 const& g)
+pegasus::ParticleStaticField::ParticleStaticField(glm::dvec3 const& g)
     : m_gravity(g)
 {
 }
 
-void pegasus::ParticleGravity::UpdateForce(Particle& p)
+void pegasus::ParticleStaticField::UpdateForce(Particle& p)
 {
     if (!p.HasFiniteMass())
     {

diff --git a/demo/Falling.cpp b/demo/Falling.cpp
@@ -211,6 +211,7 @@ void FallingDemo::SceneReset()
         );
         m_particles.back().SetVelocity(randDouble(), randDouble() - 5, randDouble());
         m_particles.back().SetDamping(1.0f);
+        m_particles.back().SetMass(1e6);
     }
 
     //Create rigid bodies
@@ -238,15 +239,26 @@ void FallingDemo::SceneReset()
         }
     }
 
-    //Create forces
-    m_forces.push_back(std::make_unique<pegasus::ParticleGravity>(glm::dvec3{ 0, -9.8, 0 }));
-
-    //Register forces
     for (auto& particle : m_particles)
     {
-        m_forceRegistry.Add(particle, *m_forces.front());
+        m_forces.push_back(std::make_unique<pegasus::ParticleGravity>(particle));
+
+        for(auto& p : m_particles)
+        {
+            if (&p != &particle)
+                m_forceRegistry.Add(p, *m_forces.back());
+        }
     }
 
+    //Create forces
+    //m_forces.push_back(std::make_unique<pegasus::ParticleStaticField>(glm::dvec3{ 0, -9.8, 0 }));
+
+    //Register forces
+    //for (auto& particle : m_particles)
+    //{
+    //    m_forceRegistry.Add(particle, *m_forces.front());
+    //}
+
     //Create contact generators
     for (auto& body : m_rigidBodies)
     {
@@ -255,7 +267,7 @@ void FallingDemo::SceneReset()
     }
 
     //Create plane particle and rigid body
-    m_particles.emplace_front();
+    /*m_particles.emplace_front();
     m_particles.front().SetPosition({1, -position * 2, 0});
     m_particles.front().SetInverseMass(0);
     m_rigidBodies.emplace_front(
@@ -269,8 +281,7 @@ void FallingDemo::SceneReset()
     AddCube({  position * 2, position, 0 }, boxSide);
     AddCube({ -position * 2, position, 0 }, boxSide);
     AddCube({ 0, position, -position * 2 }, boxSide);
-
-    AddBoundingVolumes();
+    AddBoundingVolumes();*/
 
     activeObject = m_rigidBodies.end();
     std::advance(activeObject, -1);